310 THE RHOMBENCEPHALON. 



brachium inferius; the smaller part ends in the quadrigeminal 

 colliculi, chiefly in the inferior colliculus on the same side. From 

 the medial geniculate body to the transverse and superior temporal 

 gyri, the acustic path is formed by the temporo-thalamic (acustic) 

 radiation. This completes the cortical connection of the cochlear 

 nuclei. Their reflex connections are established, first, by the 

 olivary pedicle and medial longitudinal bundle and, second, by 

 that part of the lateral fillet which ends in the colliculi of the 

 corpora quadrigemina (see pages 160 and 161). 



(3) There are Certain Special Nuclei of the Medulla. 

 These are not represented either in. the pons, above, or the spinal 

 cord, below. They are the nucleus funiculi gracilis, the nucleus 

 funiculi cuneati and the nucleus olivaris inferior. 



Nucleus Funiculi Gracilis and Nucleus Funiculi Cuneati (Figs. 

 94 and 95). The nucleus funiculi gracilis and nucleus funiculi 

 cuneati are large nuclei, extending from the level of the olive to 

 the lower end of the medulla. They are situated near the pos- 

 terior surface beneath the gracile and cuneate funiculi, whose 

 fibers terminate in them; they give origin to the medial fillet, and 

 the anterior and posterior external arcuate fibers, and they pro- 

 duce, respectively, the clava and cuneate tubercle on the posterior 

 surface of the medulla. In successive sections from below upward, 

 the nucleus funiculi gracilis is first seen as an isolated mass of 

 gray substance imbedded in the funiculus gracilis at the level of 

 the pyramidal decussation. It enlarges dorso-ventrally and 

 transversely toward its upper end, as is shown in consecutive sec- 

 tions, and reaches its greatest size at the clava, where it receives 

 the terminal end-tufts of the funiculus gracilis. At the level 

 of the clava the ventral border of the nucleus funiculi gracilis 

 fuses with the gray matter about the central canal. The axones 

 of this nucleus form about one-half of the medial fillet and the 

 external arcuate fibers. The nucleus funiculi cuneati (Fig. 95) 

 appears at the same inferior level as the nucleus funiculi gracilis. 

 It is from the first and throughout its length continuous with the 

 central gray substance on which it appears as a bud-like outgrowth 

 in the lower medulla. It gradually broadens and elongates dorsal- 

 ward when traced upward (Fig. 94). Beneath the cuneate tubercle 



